error - void value not ignored as it ought to be

Projects Programming
1

i get this error in this code, any ideas... thank you.

String inputString = ""; // a String to hold incoming data
String (key); //complet String
String (key2);
int value,number;

bool stringComplete = false; // whether the string is complete FLAG

void setup() {

// initialize serial:
Serial.begin(9600);
//reserve 200 bytes for the inputString:
inputString.reserve(200);

}

void process (int keyNumber) {

switch (keyNumber){
case 103:
delay (10);
Serial.println (" GO UP");
delay (10);
inputString = "";
// stringComplete = false;
break;
case 108:
delay (10);
Serial.println (" GO Down");
delay (10);
inputString = "";
// stringComplete = false;
break;

case 105:
delay (10);
Serial.println (" GO Left");
delay (10);
inputString = "";
// stringComplete = false;
break;
case 106:
delay (10);
Serial.println (" GO Right");
delay (10);
inputString = "";
// stringComplete = false;
break;

}

}

void conv_String (String intString) {

String val = "intString";
int result = val.toInt();
return result;
}

void loop() {

while (Serial.available()) {

String pass_inString = getString (); // Get String
delay(10);

number = conv_String (pass_inString);
process (number);
delay(10);

}

}
String getString() {
while (Serial.available()) {

delay(10);
char inChar = (char)Serial.read();
inputString += inChar;

if (inChar == '\n') {
stringComplete = true;
}

}
if (key == '\n') {

stringComplete = true;
delay(10);
}
return inputString;

}

2

A void function doesn't have a return value.

The String "intValue" doesn't have an integer value.

Please remember to use code tags when posting code

3 
int value, number;

void conv_String (String intString)
{
  String val = "intString";
  int result = val.toInt();
  return result;    ///////////// YOU CAN'T RETURN A VALUE FROM A FUNCTION THAT RETURNS 'void'
}

void loop()
{
  while (Serial.available())
  {
    String pass_inString = getString ();  // Get String
    delay(10);
    number = conv_String (pass_inString);  ///////// YOU CAN'T STORE A 'void' VALUE IN AN 'int'
    process (number);
    delay(10);
  }
}